code p0421

[dronesurfboards]

My SES light came on today and the code i pulled was P0421. I know thats the o2 sensor on the exhaust manifold, but I just changed that when the i pulled that code 2 weeks ago. Could there anything else i need to change on this...i got an 02 I4 G. I replaced the o2 sensor with a dealer replacement.

[QnzMostWanted]

did u reset it when u put in the new o2?

[dronesurfboards]

yeah i erased the code after i put the new o2 sensor in

[bronxbombr]

you do know that there is more than one sensor.

[dronesurfboards]

yeah, but wouldnt that throw another code for that particular sensor? or is it universal for both o2 sensors?

[pinoyesv6]

the cat could have gone bad.

[jusmills]

If I remember correctly the cat(s) is/are covered under a mandatory federal emissions law...7 years 70,000 miles...you may want to actually take it dealer if you fall in that range.

PO0421 is catalyst efficiency value low...so chances are if you changed both sensor, it may be the cat, since the computer is not getting the required change between the two O2 sensors.

[n3oAcid24]

if you need a cat, i have a stock one i can sell you..

[lKoRTy]

i've been getting that code after i put in my cold air intake...

[dronesurfboards]

how much for the cat? i just reset the code the other day and im hoping it was just a fluke. hasnt come up yet but if it does i might have to look into buying that cat.

[TederickR]

P0421 is the Bank 1 warm Catalyst. which is the Bank 1 Cat Converter. That is attached to the exaust manafold. I just fixed it 3 weeks ago. I ended up going to the dealer and I installed the part. Everything went fine. If you try to look for the part at o riley or auto zone. Might as well not waste your time. There is no listing. It is a dealer item. I ended up paying 254.00 for the part alone/ But different dealers have different prices.